Implement getters akin to EVM opcodes

[LucasGrasso]

Summary

Partially addresses #2653

• [n] y/n | Does it introduce breaking changes?
• [n] y/n | Is it dependent on a specific version of cargo-contract or pallet-revive?

Description

Implements the following host fns:

• fn chain_id(output: &mut [u8; 32]);
• fn balance_of(addr: &[u8; 20], output: &mut [u8; 32]);
• fn base_fee(output: &mut [u8; 32]);
• fn origin(output: &mut [u8; 20]);
• fn code_size(addr: &[u8; 20]) -> u64;
• fn block_hash(block_number: &[u8; 32], output: &mut [u8; 32]);
• fn block_author(output: &mut [u8; 20]);

[LucasGrasso]

One question related to #2597. Should balance_of return Balance or U256? I've left it as U256 following the implementation of value_transferred().

[cmichi]

@LucasGrasso As an FYI, I've changed the ink GHA setting for running the CI from

Require approval for all external contributors

to

Require approval for first-time contributors

So you no longer need someone to approve your runs.

[LucasGrasso]

So you no longer need someone to approve your runs.

Excellent, That was a bugger.
Fixed the error now, my bad it took to long to realize that the issue was actually in the comment.

[Daanvdplas]

He @0xLucca would you be interested to rebase on master so that we can finish this PR?

[Daanvdplas]

@cmichi can you help finishing this PR?

[davidsemakula]

Very nice!
See comment about BlockNumber type

[davidsemakula]

Thanks @LucasGrasso
You just need to make rustfmt happy to make this ready to merge.

[LucasGrasso]

Ran rustfmt. Thanks @davidsemakula for the review!

[cmichi]

Thank you, Lucas!

[LucasGrasso]

All set, thanks to all for your help!